That looks very good! Defects are pretty significant on the one shaft I see but as long as you smooth out the shafts a bit it it could work with lots of grease. It will be better and holding grease with all that porosity.

I was thinking more in terms of reverse engineering a new mold from an existing part. I just wonder where the mold would actually split so the cast can be removed, and how much additional work it'd still require, like drilling the necessary holes in it.

I see what you are saying. To re-cast it in halves, and yeah I don’t know exactly where the seam would be but it would be possible. The original part is made from a drawing into a steel mold and the plastic is injected at like 1000+psi. You can’t make those kinds of molds out of silicone and without that pressure you can’t make strong parts. It’s a labor intensive process for the mill and the hand cleanup afterwards but it does produce thousands of perfect parts every time for pennies.

There are newer resins that will cure at zero pressure and behave closer to thermoplastics but I haven’t tried them. I’ve been meaning to but not for a part like this since I think it’s doomed.

Let’s see how this part he made works. I’m worried it’s maybe too hard/brittle and the friction will be different in which case it should just need to have metal pins installed into it.

The plastic is a little bit elastic.If you want you can check some videos of the process, exactly it was made with the "Multijet Fusion" technology from HP, the plastic is PA12 polyamide.There is some videos on YouTube.

I see what you are saying. To re-cast it in halves, and yeah I don’t know exactly where the seam would be but it would be possible. The original part is made from a drawing into a steel mold and the plastic is injected at like 1000+psi. You can’t make those kinds of molds out of silicone and without that pressure you can’t make strong parts. It’s a labor intensive process for the mill and the hand cleanup afterwards but it does produce thousands of perfect parts every time for pennies.

I was thinking of casting it from some other material anyway, like aluminum, which wouldn't require injection molding pressures, just tolerance to extreme temperatures.

The thing that has baffled me is the difference between the final drive gear on the LD pickup vs the DVD pickup. On the DVD, the final gear is split in two with spring tension between the two halves. Any idea what is up with this?

I sure wish I did that when I needed parts back in 2013. I have two D604’s. One I have for parts as the M holder broke. The partial working D604 I’m hoping isn’t completely broke, but we definitely need a good source to keep these players going. Hopefully we hear back from miskia, soon.

I see what you are saying. To re-cast it in halves, and yeah I don’t know exactly where the seam would be but it would be possible. The original part is made from a drawing into a steel mold and the plastic is injected at like 1000+psi. You can’t make those kinds of molds out of silicone and without that pressure you can’t make strong parts. It’s a labor intensive process for the mill and the hand cleanup afterwards but it does produce thousands of perfect parts every time for pennies.

I was thinking of casting it from some other material anyway, like aluminum, which wouldn't require injection molding pressures, just tolerance to extreme temperatures.

Casting aluminum that small and precise is a job for masters. Very very hard...some pressure would help. Maybe zinc...but honestly I’d try to avoid making the part stronger than OEM. That can lead to unforeseen issues from my experience. In today’s world parts like that, if made of metal, would be made using a powdered metal forging.

blam1 wrote:

The thing that has baffled me is the difference between the final drive gear on the LD pickup vs the DVD pickup. On the DVD, the final gear is split in two with spring tension between the two halves. Any idea what is up with this?

I’d assume it’s for lash compensation (like the cam gear on a CR TDI VW) or shock mitigation (like the big swinging bridge on the LD-W1) but I don’t have a picture. Probably the laser either moves quicker when reading DVD or it needs more accuracy.

I'm not familiar with that type of plastic but the problem with the original gray MHolder is that it is too hard of a plastic which makes it brittle. The 1779 plastic is softer and allows for shock absorption. The picture of the MHolder does look really good.

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